The invention relates to a communication module with a sensor of a detection device comprising a plurality of sensors arranged in series. It also relates to a communication circuit comprising such communication modules, a sensor comprising such a communication module. It also relates to a detection device comprising such sensors or communication circuit and a method of communication implemented in such a device.
The field of the invention is the field of detection devices comprising a plurality of sensors arranged for detecting/measuring an event or a physical variable, and more particularly of devices for detecting leakage, for example of liquids of water or hydrocarbon type etc., in particular in zones with a dangerous or even explosive atmosphere, known as “ATEX zones” (for ATmosphère EXplosive [explosive atmosphere]).
There are currently numerous solutions for the detection of leakage of liquids such as leakages of water or hydrocarbons. These solutions utilize an electronic and/or computerized supervision device linked, via a cable, referred to as a detection cable, to one or more sensors arranged along this cable. The detection cable, via two wires, transports an electric signal for supplying the different sensors, provided by a supply module which can be incorporated into the supervision device. The detection cable, via one or more wires, also transports a communication signal between the supervision device and each of the sensors.
The longer the detection cable, the more powerful the electric communication signal emitted by the supervision device, for ensuring good communication with all the sensors, including the sensor situated furthest away, and avoiding parasitic energy and parasitic reactances.
Now, the increase in power of the communication signal is dangerous for ATEX zones because high-power signals can cause explosions due to the energy released through the Joule effect. This is why the power of the signals used is limited for the ATEX zones and monitored by barrier devices called “Zener barriers” positioned between the electronic supervision device and the detection cable. The limitation of the power of the communication signals has the consequence of limiting the length of the detection cable.
A purpose of the invention is to overcome the abovementioned drawbacks.
Another purpose of the invention is to propose a method and means of communication with sensors of a detection device, in particular for leakage detection, in zones with a dangerous atmosphere, without however limiting the length of the detection devices.
It is also a purpose of the invention to propose a method and means of communication with sensors of a detection device, in particular for leakage detection, limiting the energy consumed during the operations of communication with the sensors.
Finally another purpose of the invention is to propose a method and means of communication with sensors of a detection device, in particular for leakage detection, limiting the energy released by the detection device.